There are plastic / rubber hoses that carry vacuum from the engine to different compinents. Sometimes the crack or dryrot from heat. As a result, there is a vacuum leak. If you look under the hood, you should see many of them. NOTE: They are not electrical wires. Check to make sure none have come disconnected or damaged. If you are lucky, with the engine running, you may hear a hissing sound where the leak is located.
Let me know what you find. I'm sorry, but this is really hard to explaine such a simple thing. I hope I've helped.
Joe
Tuesday, September 14th, 2010 AT 8:35 PM